Carton folding mechanism



. Mmh 4, 1941. .A; E, GN O ERK 2,416,748

CARTON FOLDING MECHANISM I 4 Sheets-Sheet 1 Filed 1m 23, 1945 IIIlllFln- Maid! 94 A. E.'GNOERK CARTON FOLDING MECHANISM Filed Aug. 25,1945 4 Sheets-Sheet 2 March 4, GNQERK CARTON FOLDING MECHANISM FiledAug; 25, 1945" 4 Sheets-S heet 3 March-4, 1947 A. E. GNOERK 2,416,748

CARTON FOLDING MECHANISM v v Filed Aug. 23, 1945 4 Sheets-Sheet 4Patented Mar. 4, 1947v CARTON FOLDING MECHANISM Adoiph E. Gnoerk,Evanston, 111., assignor to Peters Machinery Company, Chicago, 111., acorporation of Illinois Application August 23, 1945, Serial No. 612,151

9 Claims.

This invention relates to machines for folding cartons preparatory to afilling operation. The hereindescribed mechanism is a development ofcertain features of folding devices in machines of th type shown in myCopending application Serial No. 585,645, filed March 30, 1945, forCarton forming and lining machine, and is particularly directed to thehandling of a special form of carton.

The main objects of this invention are to provide an improved form ofcarton folding mechanism wherein hook-shaped tabs formed on the endflaps of the opposite sides of a carton are caused to engage slits ofhook-form formed in the end flaps of the bottom of the carton; toprovide improved means for folding the side and end flaps with respectto the bottom of the carton; improved means for retracting the hookshaped tabs for entrance into the hook-shaped slits, and improved meansfor tucking and forcing the tabs into proper engagement with theirinterlocking slits.

A specific embodiment of this invention is illustrated in theaccompanying drawings, in which:

Figure 1 is a fragmentary front elevation of the folding mechanism andsome of the associated structures of the machine.

Fig. 2 is an end view of the same with some parts shown in elevation andsome in section.

Fig. 3 is a perspective view of the same with a portion of the tablebroken away so as to illustrate some of the mechanism that wouldotherwise be hidden thereby.

Fig. 4 is a plan of a carton blank and liner of the form for which thehereindescribed folding mechanism is designed.

Fig. 5 is an end elevation of the carton showing the same in partlycompleted folded relation of its parts.

Fig. 6 is a corresponding view showing the manner in which the sideportions of the carton are swung outward in order to retract the lockingtongue to a position for entrance into the looking slit of the endflaps.

Fig. '7 is a similar view showing the side portions pushed inward to apoint beyond the vertical, being a position which these parts occupyafter the completion of tucking operation, the overthrow assuring thatthe parts will be permanently interlocked when the sides are returned totheir vertical positions.

In the form shown in the drawings, the supporting frame of the machinecomprises a table I and a pair of vertical guideways 2 for cross bars tvhich are carried by a pair of endless conveyor belts, not shown, whichcause the cross bars 3 (of which only one is shown in the drawing) totravel vertically downward through an opening 4 in the table. Each ofthe cross bars 3 is provided with a vertical fin 5 at each end thereofthat travels in the guideway 2 in a straight vertical path, from theposition in which it is shown in the drawings,

through the opening 4 to a point below the flap foding deviceshereinafter described.

Each cross bar 3 carries a form block 6 having its rectangular bottom Iof the same shape as the bottom panel of the carton which is to befolded. The opposite side faces 8 are inclined inwardly and upwardlyfrom the vertical and the end faces 9 are vertical and each end face 9is formed with a tucking depression Ill and with a pair of spacedvertical grooves l I.

The type of carton blank for which the present machine is particularlydesigned is illustrated in Fig. 4 and consists of a cardboard body ofthe form shown in Fig. 4, which may be overlaid by a rectangular linersheet l2. If the liner sheet I2 is of extremely thin material, such asCellophane, it should be appropriately spot-pasted to the carton blankbut if it is of heavier material, it need not be attached to the blank.

The carton blank is scored n a plurality of transverse score lines l3and longitudinal score lines Hi to define a front end panel I5, a bottompanel [5, a rear end panel [1, a topv panel 18, a

top securin front flap I 9, bottom end flaps 29, side end flaps 2| and22, top securing end flaps 23, and inner wing flaps 24 which areattached to the top edges of the front'side Wing fiaps 2|. The end flaps20 are provided with closure slits 25 which have the main portionthereof parallel with the scores I 4 and their end portions 26 curvedinwardly toward the outer-ends of the flaps 26. The flaps 2| and 22 areshaped to form hooked tabs 21 positioned to interlock with the slits 25when the carton'is folded, and having shoulders 28 positioned to engagethe sides of the inturned ends of slots 26. The cover panel 18 of thecarton is provided with closure flaps 23 and I9 on its unattached edges,which flaps coact with the slits 25 in the bottom end flaps 29 and theslit 39 in the front side panel when the carton is carton blanks aredelivered successively in proper timed relation to the arrival of theform blocks 6, to a position above the top of the table andwith thebottom panel of the carton blank in registering alinement with the pathof movement of the bottom 1 of the forming block 6.

As the carton blank is pressed by the forming block 6 downwardly throughthe opening 4, its

7 bottom end panels 20 are folded upwardly by shoulders 3|, which areformed at the inner ends of bars 32, mounted on the table so as tooverhang end'portions of the opening 4; The bars 1 32 are spaced inwardfrom the sides of opening 4 and the inner ends of the bars 32 are bentdownwardly to form thin blades 33 directed along the path of the formingblocks 6. r

Shoulders 34, formed by the sides of the open- I ing 4 in the table,coact with the bottom edges 35 of the forming block 6 to bend up thefront side panel l5 and the rear side panel "of tire carton. In view ofthe fact that the shoulders 3| engage the carton blank in advance of itsbeing engaged by the shoulders 34 as the, forming block 6 passes throughthe table, the end flaps 2B are i turned up in advance of the turning upof the front and rear panels of the carton. Form blocksv 36 attached tothe table have warped surfaces 3!) Whloh cooperate with the blades 33 tofold the end flaps 2|, 22. 23 and 24 against the ends 9 of the formingblock and into the position in which these parts are shown in Fig. 5.These end flaps are thereafter held in place by guiding plates 33.

Attached behind the guide plates 33 and extending through an aperturethere n are sprin s 39 wh ch frictionally engage the locking tabs 2! ofthe side end flaps 2| and 22, causing them to be retarded frictionallyas the forming block 6 moves downwardly, The result of this retardationis to cause the side panels to swing outwardly as indicated in Fig.6,

It will be seen from'this figure that when the parts are in th sposition, the tabs 21 are retracted to a position above the slits in theend flaps 20. A second'set of springs 40, somewhat stiffer than thesprings 39, next engage the tips of the tabs 21 in such manner as topress them into the d ression It in the form block to open the slits 25;

When the parts of the carton are in this position. the side panels ofthe carton will be engaged 9 shafts 43 and 44 respectively and theseshafts arerotated by oppositely directed lever arms 45 and 46 connectedby a cross link 41. The shaft 43 has a crank arm 48 carrying a roller 49which rides ron cam 50 carried by shaft 5|, Springs 52 and 53 normallyurge the plates 4! and 42 outward against stop rods 54.

The structure of mechanism for driving cam 50 in timed relation to thesuccessive arrivals of forming blocks 6 in position for cooperation withthe plates and 42 is well known in this art and has been omitted fromthe drawings in order to simplify the disclosure of the mechanicalelements that directly coact with the carton blank to accomplish thefolding operations. i

Adjusting screws 55 with lock nuts 56 regulate the pressure of thetucking springs 48.

The operation of the device shown is as follows:

The conveyor belt, not shown but of which is to be understood tocomprise a series of bars 3, care ries a succession of uniformly spacedblocks 6 which are guided by the fins 5 of the bars 3 riding in theguideway 2 so as to travel in a vertical path downwardly through theopening 4 in the table I of the machine. A complete machine of thegeneral type to Which this invention is applicable is illustrated in myaforesaid copending appiication. It will however be understood by thoseskilled in the art that the shaft 5i is suitably geared into theoperating mechanism, as for example to an adjacent sprocket-carryingshaft of the conveyor, so that the rotation of the shaft 5! will beaccurately timed to swing the plates 44 and 42 inwardly at the instantwhen the forming block 6 arrives at the position where the slits 25 ofthe carton reach the lower ends of the tucking springs 40; When a formblock 3 arrives at about the position in which it is shown in Fig. 3, acarton blank together with its liner, if it has one, is supplied bydelivery devices, not shown, and caused to settle down on the table withits bottom panel It in registration with the folding shoulders 3| and 34which surround and define the path of the bottom l of the form block 6.The downwardly moving form block now forces the carton through thetable; the shoulders 3i first cause the bottom end flaps 25 to be foldedupward on their score lines l4; and then the front and rear portions ofthe carton are folded upward on the score lines I3 of the bottom panell6 as the bottom 1 of the form block passes the shoulders 34 wh ch arespaced below the level of the shoulders 3!.

During the stage of the folding operation, the end flaps 2| and 24 ofthe front panel E5 of the carton and the end flaps 22 and 23 of thepanels I! and [8 of the carton remain in planar alinement with theirrespective panels and pass downwardly through the slot-like spaces 5!between the bars 32 and the table edges that form the shoulders 34.

The warped surfaces 3'! of the blocks 35 then act, through the movementof the form block, to fold these end tabs inwardly so that they overliethe end flaps 20 and pass downwardly between the blades 33 and the endfaces 38.! of the blocks 33, Fig. 3. The parts of the carton now occupythe relative positions in which they are shown in. Fig. 5. When the tabs2? of the carton come into contact with the friction springs 39, theside portions of the carton will have passed clear of the table and willbe swung, by frictional engagement with the springs 39, to the positionin which they are shown in Fig. 6, with the panels H and i8 lyingagainst the plate 42 and the panel I5 lying against the plate 4! of thefolding mechanism. The abutments 54 limit the outward movement of plates4| and 42 against which the sides of the carton can be shifted under theaction of friction springs 39. Thus the abutments 54 limit the retractedpositions to which the tabs 21' of the carton folds can be moved by thefriction springs 39.

The carton next reaches the point where the tucking springs 49 press thetabs 21 inwardly into the depressions ll) of the forming block above theslit 25. The cam 54 now causes the plates 2 to swing inwardly carryingthe carton parts to the relative positions shown in Fig, 7. Duringenema.

this last mentionedmovement thetucking-springs 40 guide tabs 21 sothatthey enterthe slits 2-5 causing barbs 28- to interlock with the hookportions 26' of theslits l The overthrow indicated in Fig. '7" assures aproper interlocking of these parts, so that'when'the side panel l1moves'backto'a vertical'position, it completes the interlock 111g-After'the carton has been thus formed; it is removed from the blockandthefilling and clos-- ing of the carton is completed bydevi'ceswhicli are not a part of the present invention.

Although but one specific embodiment of this invention is herein shownand described, itwill beunderstood that numerous d'etails ofthe structure shown may be altered or omitted without departing from the spiritof this invention as defined by the following claims.

I- claim:

1. In a machine for forming a carton blank shaped to provide bottom andsidepanels having end flaps shaped and positioned. to overlap oneanother to form an end panel of, the finished carton, one of said sidepanel end flaps having a locking tongue and another of said end fiapshaving a slot to receive said tongue, the combination of a travelingform block, stationary guides positioned aboutthe path of said block andacting in overlapping succession tofold said bottom end flaps againstsaidblock, then :to fold said side panels against said block, and thento fold said tongued end flap against said block in overlapping relationto said slotted end flap, said last-named stationary guide comprising asurface of double curvature leading from alinement with the respectiveside panel guide to a position at right angles thereto.

6; 4 In a machine for forming a. carton blank shaped to provide bottomand side panels hav ing-'end'flaps shaped and'positioned to overlap oneanother toiform an end panel of the finished car-- ton; oneof, said sidepanel end flaps having a locking tongue and'another of said end fiapshaving a slotto receive said tongue, the combination of a traveling formblock, means coacting with said blockto fold said sidepanels and endflaps against said block to form .the carton, a frictionspringpositioned-to bear on the tongue bearing flap toretard its" movement toswing the tongue into position to enter said slot, a stationary tuckingspring bearing on said tongue to open saidslotand guide said tongue, andmeans for swinging said tongue into said slot.

5. In a machine for forming a carton blank shaped to provide bottom andside panels having end flaps shaped and positioned to overlap oneanotherto form an end panel of the finished carton", one of said side panel endflaps having a: locking tongue and another of said end flaps havingaislot to receive said tongue, the combination of a traveling formblock, means coacting with said block to fold said side panels and endflaps against said block to form the carton, a friction springpositioned to bear on the tongue bearing flap to retard its movement toswing the tongue. into position to enter said slot, a station- 2. In amachine for forming a carton blank I shaped to provide bottom and sidepanels having end flaps shaped and positioned to overlap one another toform an end panel of the finished carton, one of said side panel endflaps having a locking tongue and another of said end flaps having aslot to receive said tongue, the combination of a traveling form block,stationary guides positioned about the path of said block and acting inoverlapping succession to fold said bottom end flaps against said block,then to fold said side panels against said block, and then to fold saidtongued end flap against said block in overlapping relation to saidslotted end flap, said bottom end flap guide being spaced inward fromsaid side panel guide and having a blade extending along said path tohold said bottom end flap against said block, and said tongued-end-flapgu de comprising a surface of double curvature leading from a positionin alinement with the respective side panel guide to a position adjacentto and parallel with said blade.

3. In a machine for forming a carton blank shaped to provide bottom andside panels having end flaps shaped and positioned to overlap oneanother to form an end panel of the finished carton, one of said sidepanel end flaps having a locking tongue and another of said end flapshaving a slot to receive said tongue, the combination of a travelingform block, means coacting with said block to fold said side panels andend flaps against said block :to form the carton, and a friction springpositioned to bear on the tongue bearing flap to retard its movement toswing the tongue into position to enter said slot, tucking means bearingon said tongue to open said slot and guide said tongue, and means forswinging said tongue into said slot,

ary tuckingspring bearing on said tongue to open said slot and guidesaid tongue, and means for swinging. said tongue into said slot, saidlastnamed means comprising a cam actuated plate bearing on therespective side panel of the carton.

6. In a machine for forming a carton from a shaped blank comprising sideand bottom panels and end fiaps attached to said panels including a pairadapted to occupy overlapping positions in the finished carton, onemember of such pair having a locking tongue and the other member havinga slot to receive said tongue, the combination of a traveling formblock, means for wrapping the carton blank about said form block throughthe movement of said block, a friction spring adjacent the path of saidblock in position to engage said tongue bearing flap and shift it to aretracted position with respect to said slot, abutment means to limitsuch shifting of said tongue bearing flap, a second spring positioned tobear on said retracted tongue to open said slot, and means timed tocoact with said second spring for tucking said tongue into said slot.

'7. In a machine for folding a carton comprising bottom and side panelshaving flaps at their ends adapted to overlap to form end panels, eachbottom end flap having a tongue-receiving slot therein, and each sideend flap having a tongue formed thereon for insertion into the slot inthe corresponding bottom end fiap, the combination of a forming blockhaving an end shaped to register with said bottom panel and mounted totravel in the direction faced by its said end, a

pair of guides having parallel shoulders lying in a plane transverse tothe path of said block and coacting therewith to fold said bottom endflaps against said block and having blades extending along the path ofsaid block, other guides having parallel shoulders positioned to foldsaid side panels against said block and spaced from the outer edges ofsaid blades to provide passages for the end flaps on said sides, meansproviding warped surfaces extending from said side panel foldingshoulders outside of said blades for folding said side panel end flapsagainst the outer faces of said blades. 7

8. In a machine for folding a carton comprising bottom and side panelshaving flaps at their ends adapted to overlap to form end panels, eachbottom end flap having a tongue-receiving slot therein, and each sideend flap having a tongue formed thereon for insertion into the slot inthe corresponding bottom end flap, the combination of a forming blockhaving an end shaped to register with said bottom panel and mounted totravel in the direction faced by its said end, a

pair of guides having parallel shoulders lying in a plane transverse tothe path of said block and coacting therewith to fold said bottom endflaps against said block and having blades extending along the path ofsaid block, other guides having parallel shoulders positioned to foldsaid side panels against said block and spaced, from the outer edges ofsaid blades to provide passages for the end flaps on said sides, 'meansproviding warped surfaces extending from said side panel foldingshoulders outside of said blades for folding said side panel end flapsagainst the outer faces of said blades, guide walls for loosely holdingsaid side end flaps in their folded positions, meanslengaging said sidepanel end flaps to swing said side panels outward to carry their tonguesrearward of said slots, stationarytucking springs positioned to bear onsaid tongues to open said slots, and means coacting with said tuckingsprings to swing said side panels against said block and cause saidtongues to enter said slots. 9. A carton forming machine, comprising arected along the path ofthe block and being spaced inwardly from saidside guides, and side' flap folding guides presenting concave guidesurfaces ofdouble curvature extending along. the path of said blockaround the portions of said blades that are next adjacent to saidshoulders and commencing at a position of alinement with said sideguideshoulders and ending at a position of parallelism with and close tosaid blades.

ADOLPH E. GNOERK:

REFERENCES CITED I The following references are of record in the file ofthis patent:

' UNITED STATES PATENTS Number Name Date 1,025,880 Peters May 7, 19121,957,957 Hartman May 8; 1934 2,146,407 Rose Feb. 7, 1939 1,430,232Horton Sept. 26, 1922 FOREIGN PATENTS Number Country Date 507,058 GreatBritain June 1, 1939

